Sims Social Slob Trait

On the last happy new year quest one of the task requirements is you must have or equip sim with sims social slob trait
slobs are relatively unconcerned by mess and even thrive in filth.. much to other sims’ dismay

how to find and equip slob trait in sims social ?
actually it’s already explained on the first time when you play this game
if you forgot click your sims, there will be traits option to choose

assign traits to give your sim unique abilities

you must have enough lifetime points to equip or remove it, i’m sure you already have enough lifetime point from skills and missions